Metal cans are often produced as two piece cans which comprise a cylindrical can body with an integral bottom wall and a can top. The can is typically made from aluminum. Typically, curved sections are formed at the bottom and top of the can to increase its structural integrity. A can making machine, sometimes referred to as a necker, forms the curved sections of the can by progressively squeezing, i.e. necking, the can body between opposing ram bodies which squeeze the can. The ram typically includes one or more cam followers extending therefrom. The cam followers ride on a cam that is mounted on a cylinder. As the ram rotates about the cylinder, the cam follower rides on the cam, which is configured to move the ram back and forth.
Typically, the cam is inserted into a tire to enhance operation thereof. The tire facilitates a smooth transition of force between the cam and the remaining portion of the cam follower. Moreover, the tire inhibits wear of the cam, the remaining portion of the cam follower, the ram, and, more generally, the necker machine. A disadvantage of known cam followers for rams of necker machines is that over time and with extended use, the tire tends to shift axially relative to the remaining portion of the cam follower, and more specifically the outer ring. If this problem is not corrected, it can lead to reduced performance of the necker machine, and can further require unscheduled or more frequent maintenance or repair.
Cam followers can include two bearings (e.g., roller or ball bearings) mounted adjacent to one another on a stud. The bearings have a predetermined first axial width and a first manufacturing tolerance of plus or minus a fraction of the first axial width. When two of the bearings are assembled on the stud adjacent to one another the combined axial width of the two bearings has a “stack-up” tolerance that depends on the individual tolerances (e.g., first manufacturing tolerances) of each of the bearings. The two bearings are typically installed between two radially inward projecting shoulders of the tire in which outer rings of the bearings are disposed. The tire has a second axial width defined between the shoulders. The second axial width has a second manufacturing tolerance of plus or minus a fraction of the second axial width. Thus, when the first manufacturing tolerance of the bearings is on the low end and the second axial tolerance of the tire is on the high end, the combined axial width of the two bearings could be less than the second axial width between the shoulders. This creates an axial gap between an axial inward portion of the shoulder and the adjacent bearing. This axial gap allows the tire to move axially on the bearings. Such axial movement of the tire relative to the bearings could cause premature failure of the cam follower.
Thus, there exists a need to accommodate such manufacturing tolerances and to provide a cam follower in which axial movement of the tire relative to the bearings is reduced or eliminated.